This proposal is an application for a Small Grant to initiate a project on the mental health effects of congenital abnormalities of the sex organs (CASO) indicative of prenatal hormone deficiences that are likely to affect brain development as well. The study is designed to test the appropriateness of hypotheses and feasibility of subject recruitment and of assessment methods for a subsequent larger study with more statistical power. Target subjects are 20 genetic males, age 6-10 years, who were born with a small penis which is indicative of chronic impairment of prenatal androgenization, and who were raised as boys. There will be two control groups: (1) 20 males born with minor genital defects and normal-sized penises in which a chronic prenatal androgen deficiency is not suspected as an etiologic factor; these subjects will be matched to the target boys on relevant demographic variables. (2) Approximately 10 genitally normal brothers of the target subjects that fall into the same age bracket. Psychosocial (including gender) and cognitive development as well as psychiatric impact will be assessed by means of semistructured interviews, questionnaires and psychometric tests with the child and, independently, the mother. This will be the first systematic controlled study using standard instruments of gender and psychiatric development in boys with congenital abnormalities of the sex organs attributable to deficient prenatal androgenization. If successful, the study will be expanded to adolescent and adult patients. The long-term goal is the development of empirically validated criteria for the sex of assignment of intersex newborns and for preventive strategies of psychosexual management during childhood and adolescence for these children.